XMM-NEWTON SCIENCE DATA IMAGES

The images in this XMM-Newton gallery have been created using the ESAS
tasks in SAS. The individual observations have been temporally
filtered to remove periods of strong soft proton contamination and
then corrected for the quiescent particle background and the residual
soft proton background. The images have been been corrected for
exposure and the effects of possible different filters on the three
EPIC instruments. Finally, the images have been adaptively smoothed.
The processing methodology was discussed extensively in Snowden et al. 2008,
and the use of the SAS ESAS tasks is explained in the ESAS Handbook.

The images are processed in three bands, 0.4-0.75 keV, 0.75-1.3 keV,
and 2.0-7.2 keV. For each object there are jpeg images in the three
individual bands, a combined soft band (0.4-1.3 keV), and a
false-color image (red: 0.4-0.75 keV, green: 0.75-1.3 keV, blue:
2.0-7.2 keV). FITS images for the three bands are also available.
For each object there is a list of individual observations (ObsIDs)
that cover the field. ObsIDs with '**' in the second column have been
used for the mosaic, a 'c' in the second column indicates that the
ObsID was too strongly contaminated by soft protons to be useful.

Images at other Wavebands: Some objects have either
DSS or WISE 22 micron images on the same scale as the X-ray false-color
images. These are generated using the HEASARC
SkyView
facility.

Caveats: The objects have been processed uniformly on a
'good-enough' basis. Some individual observations could probably benefit
from a more stringent data reduction and certain other observations are
so strongly affected by residual soft proton events that there is some
effect noticeable in the mosaicked image. This is most readily seen in
the hard band images where there is little emission from the object.
The SNR RXJ1713-3941 and the galaxy cluster Abell 2256 are good example
of this effect.

A second source of processing artifacts originate in the mosaicking process.
In order to combine data from different instruments and possibly different
filters a spectrally dependent scaling must be used. If the source spectrum
is significantly different from the assumed spectrum a mismatch can occur.
This doesn't happen often, but the false-color image of the Perseus cluster
shows some evidence for it.

A third artifact can be seen when exposure varies significantly across the
field. In this case the scale length of the adaptive smoothing will vary
leading to a variable clumpiness in the image. The image of S308 is a good
example of this effect as the central pointing has an order of magnitude
higher exposure than the outer pointings.

And an Invitation: Creation of the Science Image Gallery
will be a long-term project pursued as time allows. The order as to which
observations are done first is arbitrary and if you have a request, let the
GOF know through our Help Desk at: xmmhelp@athena.gsfc.nasa.gov.